1070908: Don't count cpus without topo for lpar

ppc64 lpar systems create /sys/devices/system/cpu/cpu*
entries for each cpu thread available for the physical
hardware. Previous assumption was only cpus allocated
to a machine/guest/lpar had sys entries as on other
arches.

Now, we ignore sys cpu entries without topology
information while counting total numbers.

The wrong total cpu count was throwing off total
cpu socket count as it's based on
cpu threads/threads per core/cores per socket.

Update some hwprobe test cases to mock this.